netdev - Re: INFO: rcu detected stall in ndisc_alloc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <eeb95c52-5bf8-d3ce-d32b-269aa86bcd93@i-love.sakura.ne.jp>
Date:   Thu, 3 Jan 2019 02:06:58 +0900
From:   Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
To:     Dmitry Vyukov <dvyukov@...gle.com>
Cc:     syzbot <syzbot+ea7d9cb314b4ab49a18a@...kaller.appspotmail.com>,
        David Miller <davem@...emloft.net>,
        Alexey Kuznetsov <kuznet@....inr.ac.ru>,
        LKML <linux-kernel@...r.kernel.org>,
        netdev <netdev@...r.kernel.org>,
        syzkaller-bugs <syzkaller-bugs@...glegroups.com>,
        Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
        Linux-MM <linux-mm@...ck.org>
Subject: Re: INFO: rcu detected stall in ndisc_alloc_skb

On 2018/12/31 17:24, Dmitry Vyukov wrote:
>>> Since this involves OOMs and looks like a one-off induced memory corruption:
>>>
>>> #syz dup: kernel panic: corrupted stack end in wb_workfn
>>>
>>
>> Why?
>>
>> RCU stall in this case is likely to be latency caused by flooding of printk().
> 
> Just a hypothesis. OOMs lead to arbitrary memory corruptions, so can
> cause stalls as well. But can be what you said too. I just thought
> that cleaner dashboard is more useful than a large assorted pile of
> crashes. If you think it's actionable in some way, feel free to undup.
> 

We don't know why bpf tree is hitting this problem.
Let's continue monitoring this problem.

#syz undup